Air venting valve



Nov. 7, 1944. J, UPTQN i 2,362,327

AIR VENTING (VALVE Filed March 5, 1942 Ennenfdr J'o/m 0 112 attorney part of the tank.

Patented Nov. 7, 1944 2,362,327 H AIR VENTING VALVE JohnUpton, Wayland, Mass, assignor to Ander- I son Products, Inc., Cambridge', Mass, a corporation of Massachusetts f Application March 5, 1942, Serial, No. 433,439,

' Claims. (01. 7137-122) This invention relates to hot water. heating -systems and is particularly concerned with means for eliminating trapped air from radiatorsor such other places as it may accumulate. v

In hot water heating systems, the air must be expelledfrom the system while it is being filled with water, and air that may be distilled from the water during subsequent operation must, also be vented from theradiators from time to time.

Accordingly, the present invention is concerned with a valve which is designed to opr ate automaticallyto ventv air from the radiators or from otherhigh points where airmay be trapped at the time the system is being filled, and to vent any additional air that ma'ythereafter accumulate at the points in question.

I-Ieretofore it has been customary to eliminate air from, the ,radiators through the use of a manually controlled valve. In the present invention it is contemplated that the automatically operating valve shall be connected to the radiator at the location of the previouslyreferred to manually. operated valve. Inthis way, no disturbance of .the other equipment is necessary.

vThe foregoing and other objects'of the invention will become more apparent as the description-proceeds with the aid of the accompanying drawing, in which, l I

Fig. 1 is a diagrammatic showing ofa hot water heating system of the type with which the valve of the present invention may be used. 4 Fig. 2 is a vertical crosssection of the valve. Fig. 3 is a top plan" view of the valve with cap removed. v Figs. 4, 5 and 6 show successivepositions of the various valve parts that prevail during, the venting of air through a heatingcycle: V I 7 shows means for varying the venting capacity. I

In Fig. 1, a typical'heating system is shown having a boiler 2, a heat source 4, which may be a thermostatically controlled oil'burner, of known construction, a'ndmainsi and 8 leading to risers Ill and I2 respectively, which supplyhot'water from the boiler to radiators M and [6. Return mains l8 and join in a'commonpipe'22 leading back .to the boiler. t l 1 A water supply line 24 provides the original or additional water when needed through valve 25. The system disclosed is a s c-called sealed system, but the valve of the'present invention will function with any type of system, whether sealed or open. An' expansion tank 26, connected asshown, providesfor expansion of thewater through compression of the air 27 in the upper The air venting valves that constitute the invention are shown at 28 on radiators I4 and 16. These are ordinarily connected asnear the top tocarryitaway. I HY It will be understood further that the valve of of the radiators as possible and may be attached by theuse of a suitablefitting.

It will be understood that the system justdescribed is merely. illustrative oi any hot water heating system in which air is present'befor'e the system is filled and in which, while inuse, .air is gradually distilled from the water to accumulate at the tops of the radiators and other high spots where 'thegfiow of water is not sufficient the present invention may be attached any place in, a system from which itis desired tovent trapped air. .The systemcwith which the "valve maybe used may be one inwhich either the water is heated periodicallyor" maintained at a constant temperature. The valve will give satisfactory results with systems'that are thermostatically or manually controlled;

In afsystem of the type described, when heat is supplied, the water expands and there is an increase in pressure throughout the system. That part of the. heating cycle during which the water is being heated and expanding willbe referred to as the on part-of the heating cycle,

while the other portion of the cycle, in which the burner or heat sourceis off or diminished,

.with thewater cooling and contracting, willbe referred to as the off part ofthe cycle.

The general operation of thevalve contemplates continuous venting therethrough so long as thepressure of the-trapped air is in excess of the pressure at which the valve is set; to open. That is to say, during the initial filling of the systemfthe valve 'will vent continuously until .theptrapped air. is expelled, and thereafter,

during cyclical operation of the system-such air as may accumulate willlikewise be vented continuously until the radiatorto which the valve is attached isagain filled. I By the provision of adjustment means-,;the valve can be set to vent at a pressure which will conform to the pressure developed both when the system is being filled and during subsequent heating cycles.

' Referring toIFig. 2, the valvegenerally referred to as 28, comprises a base-30 having a screw threaded nipple 323,1; its lower; end for attachment to any suitable radiator connection. A bore 33 extends vertically throughthe nipple and base. The upper end'of base30 is threaded at 34 toreceive a locking; nut 36.having anupper flange '38 suitable for engaging an "out-turned flange. 40 on the lowerend of a casing 42.

Casing 42 is divided by a horizontal partition 41 into upperan'd lowerchambers 44 and 46,? in which are contained. the valve mechanisms. m In the lower chamber is a supp'o'rting insert 48. set in a suitable cavity in'base 30. This insert has a s eriesofholes SOtherethrough which-perchamber 46. A screen 52 is held in place by insert 48 to insure against the passage of any large-size particles from-the radiatorto the valve which might affect the operation of the latter.

Insert 48 carries a vertical support 54 on which is positioned a diving bell type float 56 havin a centrally located pin 58 that normally engages with the upper end of support 54, as shown in Fig. 4. Supporting the pin .58, on the upper side of the float, is a valve member 60 undercut at 62 to provide a circular bearing surface against a rubber valve disk 84 set in a recess in the underside of partition 41. An aperture 66, aligned .with disk 64, extends through partition", and the upper end of pin I58 extends part way there-- through, thus acting as a guide for valve member There is however, ample clearance between pin 58 Land aperture 68 so as not to impede the how of airtherethrough.

Surrounding the upper end of aperture 66 is a valve seat 68 against which normally rests a .valve disk "Ill, carried by a supporting member 12 and urged downwardly 'by a spring 14. The V spring is held in position by an externally threaded disk 16 in vertically adjustable engagement with the interiorly threaded opening 18 extending through the top of the casing 42. The upper end ofthe opening .78 is closed by a cap 80. It will be noted that both disk 16 and cap 80 have passages 82 and 84 therethrough to permit the escape of air from the upper chamber to the atmosphere.

By adjustment of disk 16, the pressure exerted by spring '14 on'the upper valve "H1 may be varied. The setting of the upper valve is determined by the pressures that are normally developed in the system during filling-and during the on cycle.

In Figs. 4, and 6 are shown the positions the various valve partstake during a heating cycle. 4, the parts are shown in the position they assume during the major portion of the on? cycle and during the early portion of the on cycle. The upper valve is still unopened because that will prevail immediately following the conditions shown in Fig. 5 and during the latter part of the on cycle and the commencement of the err cycle. The upper valve has closed because of the elimination of the lower casing pressure through the closing of valve 60. r

' The operation of the valve parts in detail is as follows. Considering first the operation of the valve during the initial filling of the heating system, water valve 26, controlling the water supply, is opened, thereby admitting water to the system. As water fills the boiler and rises through the mains, the pressure of the air above will correspondingly increase. When the pressure becomes great enough, valve 10 will be forced upwardly from its seat and air will thereupon vent continuously through aperture '66 and the ports 82 and 14 to the atmosphere. The lower valve will remain open during this period, as the velocity .of the escaping gas will not ordinarily pesufiicient to drive the-float and associated parts npwardly -to. close the lower valve. When the ystem and theradiators are full, water will 'phere.

enter the lower valve chamber 46, causing float 56 to rise, thereby closing the lower valve and stopping ,Eurther escape of air. with the pres sure removed, the upper valve will thereupon reseat itself.

, As the operation of the system continues thereafter, additional 'air will be distilled from the water and will collect in the top of the radiators. The water level will gradually drop, and as a result float 56 will descend 'with the receding water, thereby .opening lower valve 60.

This additional accumulated air is thereafter vented during one or more of the subsequent heating cycles. The action of the valve for the automatic venting of this secondary accumulation ofair is as follows. During the offpart' of the heating cycle, pin 58 will rest on support 54 pressed air will be vented through aperture 66 and the: upper ports 82 and 8.4 to the atmos- As the air is vented, the pressure within the valve :will decrease. If the pressure decreases below that at which valve 10 closes, the latter valve'may then close before all of the air has been-vented. If, however, the pressure of the trapped .air is maintained, the water level in the radiators will rise until chamber .46 again receives water, thereby lifting float 56 to cause the lower valve to close, thereby cutting off further escape of air.

Immediately upon the closing of aperture 66 by the lower valve, the upward pressure against the upper valve 10 will be dissipated so that the upper valve will reseat itself,.as shown in Fig. 6, thereby providing a double seal for aperture 6.6.

Thereafter the lower valve will remain closed until the water level has dropped and the pressure within the lower area 46 decreases to an amount only slightly greater than the pressure which is required to open the upper valve. That is to say, if the pressure necessary to open the upper valve is, for example, 15 lbs. per square inch, the lower valve Bil will not fall away from the position shown in Fig. .6 to resume its normal position as shown in Fig. 4 until the pressure in lower chamber 46has dropped to apprO imaStely 15 lbs. This, of course, will not occur until the heat source has been discontinued and the water is cooling and contracting, with a corresponding reduction of pressure of the trapped air. A one-half poun per square inch pressure in excesslof' the setting of valve Ill will maintain lower .valve'lill closed. This differential will vary, however, according to the detai s of the construction.

As the water and pressure drop, the valve parts reassume the positions shown in Fig. 4, in which condition they are ready for a repetition of the cycle just described.

In order to provide ready adjustment of the spring 14, it is convenient to place suitable marking-s on the'top-of disk 1-6, as shown in Fig. 3. With'the'cap removed, disk 15 may be turned by the insertion of a screw driver in slot until the number indicating the desired pressure is alongside a reference point 88 located in the upper surface of the threaded neck. Since most hot water systems are equipped with a pressure gauge, the pressure that will be reached on each heating cycle may be readily determined and the valve adjusted accordingly.

The valve as thus far described will operate under practically allconditions that are to be found in connection with hot water heating systems. Occasionally, however, the pressure of the air being vented during filling of the system may become so great that air will escape through aperture 66 at a sufficiently high velocity to drive valve member 60 and the associated parts to closed position'as shown in Fig. 5. It would be undesirable for the valve to closeduring filling of the system before all of the air has been vented. Accordingly, if the valve is to be used in systems where very high pressures are developed with accompanying high velocities through aperture 66, it will be appreciated that any tendency of the gas flow to close the lower valve prematurely may be overcome by reducing the effective area of aperture 66 to a point where the neces sary throttling action is provided.

The variation of the effective area of aperture 66 might be accomplished by the introduction of a perforated disk-into the upper part of aper- 'heating system, comprising a casing, an aperture through the'upper part of said casing, outer and inner valve seats at the ends of said aperture and ture 66. Such a disk is shown in Fig. '7 at 90 with I of said aperture is normally open, said float' adapted to rise and close the lower end of said aperture when the water rises in said lower chamber to a predetermined level, and a loaded second valve member normally resting on said upper valve seat to close the upper end of said aperture against pressures less than a predetermineddegree, the efiective area of said first valv member against which the pressure in said lower chamber may act bein such that after said first valve member has been closed by rising liquid it will remain closed after the water has receded until the pressure in the lower chamber has also decreased to a pressure which is but slightly in excess of the pressure required to open said second valve member.

2. A valve for venting air from a hot water heating system comprising acasing, a fixed aper ture through the upper part of said casing and provided with valve seats atits ends, a first valve member of effective area substantially greater than said aperture and limited in its downward movement and capable of upward movement to of substantially greater area than said aperture, an outer valve member normally in engagement with said outer valve seat and operable to open under the influence of pressure in said casing in excess of a predetermined degree, an inner valve member adapted to engage said inner valve seat and supported in such position that the inner end of said aperture will be normally open, a float connected to said inner valve member capable of raising the latter to close the aperture upon the entrance of water into said casing above a predetermined level, the construction of said inner valve member and float being such that when the pressure in'said casing is sufficient to open said outer valve to vent air, said inner valve will remain open, but when said inner valve has been closed by the presence of water in said casing, said inner valve will be maintained closed after the water in said casing has receded to a level below that at which said inner valve was closed by casing pressures only slightly in excess of the pressure required to open said outer valve.

4. A valve for venting air from a hot water heating system, comprising a casing having inlet and outlet ports, said outlet port formed by an aperture through a fixed portion of said casing, spring pressed means for maintainin said aperture normally closed whilethe pressure within said casing is below a predetermined degree, other means for maintaining said aperture closed while water is in said casing above a predetermined level, said spring pressed means movable to open said aperture when the pressure in said casing has increased beyond said predetermined degree and while the water in said casing is below said predetermined level, and said spring-pressed means and said other means being constructed and arranged to maintain said aperture closed after it has been initially closed by water rising above said predetermined level and after the wa- 5. A valve of the type described comprising a casing having an inlet port and'an outlet port, a

engage the lower valve seat, a second valv member also having an effective area substantially greater than said aperture and normally in engagement with said upper valve seat but movable therefrom under the influence of pressure in said aperture in excess of a predetermined degree, a float connected to said lower valve member whereby the latter may be maintained in position to close the lower end of said aperture under the influence of water in said casing above a predetermined level, the weight of said first valve member and float in relation to the effective area of said first valve member. being such that pressure in said casing only slightly greater than the presopen said upper valve means will be sufiicient to partition dividing the easing into upper and lower chambers, an aperture through said partition, lower valve means forclosing the lower end of I said aperture under the influence of rising liquid in said lower chamber, and upper valve means normally maintaining the upper end of said aperture closed and operable to open when the pressure in the lower chamber exceeds a predetermined degree and said lower valve means is open, the weight of said lower valve means being so related to the effective seating area of said lower valve means that a pressure in said lower chamber slightly in excess of the pressure required to maintain said lower valve means closed following closure by rising liquid level and after the liquid has receded below the level reached in performing the initial closing operation of said lower valve means.

JOHN UPTON. 

